Hydraulic three point tractor hitch

ABSTRACT

A redesigned three point tractor hitch system engageable and disengageable by an operator without leaving the tractor seat. This comprises eliminating the present used fish eye, ball joint ends of the two lower arms and the middle upper arm and replacing with extremities that can be positioned, attached and locked from the tractor seat. The two lower arm extremities have a fixed open jaw design that attaches to the implement studs from underneath and are locked in position by extending the shaft of a hydraulic cylinder over the studs and through the center of the jaw. The upper arm is attached by a fixed and moveable jaw design that closes and latches when pressure is applied against it from the pin that is mounted in the center mask of the implement. The upper jaw is carried by a hydraulic cylinder that aids in attaching, plus controls the fore and aft movement of the implement.

PATENTS CITED

[0001] U.S. Pat. No. 2,688,865 depicts a hand operated hydraulic locks for locking any closure more particularly the trunk compartment of a motor car and is not applicable to a tractor for attaching to implements.

[0002] U.S. Pat. No. 3,312,478 is a very complex intermediate device with many moving parts and chains and offers as much of a attaching problem as those presented by conventional hitches.

[0003] U.S. Pat. No. 3,434,737 offers an intermediate device with the same problems as the prior art mentioned before in U.S. Pat. No. 3,312,478.

[0004] U.S. Pat. No. 3,561,789 solves part of the problems of attaching tractor to implement but still uses a hitch adaptor as an additional device between tractor and is of a complex design.

[0005] U.S. Pat. No. 4,125,271 relates to a tool suspension for either front or rear mounting of tools from vehicles in the form of a three point suspension for hydraulic lifting and lowering. Front and rear mounted tools are used on motor vehicles for road maintenance, snow clearing, street cleaning and grass cutting. No adaptation was found for use with farm implements.

[0006] U.S. Pat. No. 5,029,650 is a steel frame mounted on a tractor to attach implements to. No weight or cost factor is known.

[0007] U.S. Pat. No. 5,743,339 discloses a two part steel plate device. One plate is attached to the three point hitch of the tractor and the other plate is attached to the implement. Steel plate of a size and strength to accomplish the task would be very heavy. Another drawback too this system is that there are no provisions for the fore and aft movement of the implement during operation. A still further problem is a matching plate would have to be purchased for each implement used. This represents a substantial investment for the operator.

[0008] U.S. Pat. No. 5,975,216 is a low profile transferable hydraulic three point hitch designed for use on the front or rear of a truck. The truck can then be used to attach to three point implements instead of using a tractor.

[0009] U.S. Pat. No. 5,997,024 deals with a hitching mechanism for tractors to aid in steering the implements in specific agricultural uses such as in a track laying application where both a steering function and a lateral shifting capability in needed. This is a specialized function and not needed for general use of tractors.

[0010] None of the prior art cited solved the three point hitch problems without the use of an intermediate device.

BACKGROUND OF THE INVENTION

[0011] This invention relates to a redesigned and improved three point tractor hitch for easily and quickly connecting and disconnecting to an implement.

[0012] The present three point hitch system was originally designed for use by two people in connecting implements. One person driving the tractor and one person on the ground attaching the two lower arms which require a precise alignment at the same time. With two people, one arm can be attached and then with a very slight forward or backward movement of the tractor, the other arm attached. For one person, this becomes an onerous task of much back and forth movement of the tractor and much mounting and dismounting of the tractor seat. With one arm attached and one arm loose this can become a dangerous safety hazard should the tractor move and the operator get caught between the tractor and the implement.

[0013] The upper center arm is just as precise too attach. It has to be readjusted in length everytime a different implement is used. This becomes very time consuming because it is extended and retracted by manually screwing a turnbuckle in or out.

[0014] An effort to solve these problems has resulted in a variety of aftermarket inventions. Each solution requires the purchase and use of an additional intermediate device that has too be attached to the tractor to connect too the implements.

[0015] The patent sought after solves these problems by redesigning the tractor hitch itself so as too eliminate the need of additional devices and still present a quick, easy system to attach tractor to implement without dismounting from the tractor seat.

[0016] Only the ends of the arms that attach to the implements are being redesigned. This can be accomplished at the point of manufacture or as an after manufacture modification.

[0017] This presents a safer and less physical system and offers opportunity for a much broader audience too use.

[0018] The use of additional devices adds considerable weight to the tractor and represents an additional investment for the operator.

SUMMARY OF THE INVENTION

[0019] It is an important object of the present redesigned and reconstructed hitching system to provide an automated tractor hitching system which may be readily aligned and secured without the operator leaving the tractor seat and without the use of any intermediate devices.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 Shows a three dimensional side view of an agricultural tractor with a portion of the left wheel removed depicting the embodiment of the redesigned three point tractor hitch system.

[0021]FIG. 2 is an inward side view of the fixed jaw in the open position with the hydraulic shaft in the retracted position.

[0022]FIG. 3 is the outward side view of the fixed jaw in the closed position by extending the hydraulic shaft.

[0023]FIG. 4 is a three dimensional top view of the upper fixed and moveable jaw as seen by the operator from the tractor seat.

[0024]FIG. 5 is a three dimensional bottom view of the upper fixed and moveable jaw as it is being lowered to attach to the pin mounted in the upper center mask of an implement.

[0025]FIG. 6 is a side view of the upper jaw in the open position.

[0026]FIG. 7 is a side view of the upper jaw in the closed position.

[0027]FIG. 8 is a diagram of hydraulic plumbing and electrical wiring schematics for the redesigned three point tractor hitch.

[0028]FIG. 9 is a side view of the lower arm of the three point tractor hitch as comes standard on tractors.

[0029]FIG. 10 is a side view of the upper center arm as comes standard on tractors.

DESCRIPTION OF A PREFERRED REDESIGNED EMBODIMENT

[0030] Please refer to FIG. 9 for a preview as to the present design for the two lower arms of the three point tractor hitch.

[0031]FIG. 1 shows the leading end of arm 5 is connected to the tractor 46 by the ball joint 8. The trailing end of arm 5 is then connected to the implement 30 lower stud 31 by a ball joint.

[0032]FIG. 10 shows the present used upper middle tractor arm.

[0033]FIG. 1 shows how this arm 10 is connected to the tractor 46 by ball joint 24. The trailing end of arm 10 is then connected to the implement 30 upper center pin 33 by a ball joint.

[0034]FIG. 10 also shows the turnbuckle 32 which is used to extend or retract arm 10.

[0035] The following will illustrate a redesigned three point hitch for automatically securing an implement for pulling and lifting by a motorized power source.

[0036] Referring to FIG. 1 an agricultural tractor is indicated generally by the reference numeral 46. The tractor 46 depicts a seat 40 for the operator and general operating controls 42 a hydraulic control valve and 50 a steering wheel.

[0037] A portion of the left rear wheel 48 has been removed to show various components of the tractor and hitch that otherwise would be obscured from view.

[0038] The two lower arms 1 and 5 are pivotally connected to the tractor by ball joint 8 on the lead ends.

[0039]FIGS. 2 and 3 illustrate how the trailing ends of the two lower arms 1 and 5 have been redesigned, comprising a transverse fixed open jaw 2 and a hydraulic actuated cylinder locking shaft 4. The mouth of the open fixed jaw 2 has sufficient width to readily enclose the lower hitch studs 31 of an implement 30. The combined wediths of the two fixed jaws 2 enable the operator to back the tractor 46 (FIG. 1) and attach to an implement 30 (FIG. 1) without the tractor being in perfect alignment horzinally, vertically or laterally.

[0040] In operation FIGS. 2 and 3 illustrates how the two lower arms 1 and 5 with the fixed open jaws 2, are positioned under the lower hitch studs 31 of an implement 30. As arms 1 and 5 (FIG. 1) are hydraulicly raised by the tractor arm 47 (FIG. 1) the jaw 2 encompasses the implement studs 31 on the bottom, forward and rearward side. The hydraulic cylinders 3 and 6 (FIG. 1) are actuated by engaging controls 42 (FIG. 1) extending the locking shafts 4 (FIG. 2-c) above and over the implement studs 31, fully encompassing the studs. The shafts 4 move into a locked position by entering the jaw from the opposing sides as illutrated by FIG. 3.

[0041] In reality, the horzinal width between the implement studs 31 are seldom the excact amount from implement to implement. To overcome this problem FIG. 1 illustrates how a hydraulic cylinder 9 is attached to the right (or left) lower arm 5 or 1. This enables the operator to change the distance (FIG. 1-a) between the trailing ends of the arms 1 and 5 to accomdate the different implement width. The opposing arm is general left in it's original position.

[0042]FIG. 1 shows the three point hitch also includes a center upper arm 10 which is pivotally connected to the tractor 46 by a ball joint 24 on the leading end.

[0043]FIGS. 4, 5, 6, and 7 illustrate how the upper middle arm turn buckle and trailing end have been replaced by a hydraulic cylinder 23 and a fixed 11 and moveable jaw 12 combination. Implements 30 when not in use, are never parked in the exact fore or aft position relative to the lower hitch studs 31 (FIG. 3). The upper fixed jaw 11 and moveable jaw 12 are therefore carried by a hydraulic cylinder 23 enabling the operator to extend or retract the entire jaw 11 and 12 to a proper distance to engage the pin 33 (FIG. 5) mounted on the center mask of the implement 30 (FIG. 5).

[0044] Refering again to FIGS. 4, 5, 6, and 7 in operation, the operator positions the fixed 11 and moveable jaw 12 over the pin 33 in the center mask of the implement 30. With the lower half moveable jaw 12 in the open position as in FIG. 5, the upper fixed jaw 11 is pressed down over the pin 33 mounted on the implement 30. As pressure is applied, the pin 33 moves upward between the two slide surfaces of the lower moveable jaw 12 and it is forced to rotate upward (FIG. 6.D) until it engages a latching block 13 mounted on the top of the fixed jaw 11. This rotating action of the lower moveable jaw 12 (FIG. 6.D) in relation too the fixed upper jaw 11 fully encompasses the implement pin 33 and locks the jaws closed simultaneously as illustrated in FIG. 7.

[0045] To disengage the upper jaw 11 and 12, the operator with one hand, can grasp the latching block release handle 19 and the hydraulic cylinder handle 18. By closing these handles together, the release handle 19 (FIG. 4-B) depresses the latching lever 14, collapsing the latching lever spring 15. With the latching block 13 released from the moveable jaw 12, the operator can lift the fixed 11 and moveable jaw 12 clear of the implement pin 33, disengaging the upper arm from the implement FIG. 5-30.

[0046]FIG. 6 and 7 do not show the fixed 11 and moveable jaw 12 attached too an implement pin 33 so a better view and understanding could by had by an observer.

[0047] The controls of a hydraulic cylinder are heavy and cumbersome. FIGS. 1 and 8 illustrate how an electric valve 22 is mounted and employed to actuate the upper arm 10 hydraulic cylinder 23. The electric valve 22 is used as a control device to actuate the hydraulic cylinder 23 by way of a remote thumb switch 20 mounted on the handle 18 of the hydraulic cylinder 23. An operator can with one hand, both position and manoeuver the upper center arm 10 and jaw 11 & 12 into an attaching and detaching configuration with relative ease.

[0048] This explanation of FIG. 8 will help an observer better understand the hydraulic plumbing and electrical wiring necessary to facilitate the use of hydraulic actuated cylinders 3, 6, 9 and 23 plus the application of an electric valve 22 to actuate hydraulic cylinder 23.

[0049] Hydraulic fluid, under pressure, leaves the tractor hydraulic pump 49 and passes through a hydraulic hose 100 to the electric valve 22. The electric valve 22 serves as a junction box for the hydraulic fluid to be distributed either to the upper arm cylinder 23 or to the lower arm cylinder 3, 6 and 9. If the upper arm cylinder 23 is not being actuated the fluid passes through the electric valve 22 on to the manual control valve 42 by hose 101. If no cylinders are being accuated by the manual valve 42 the fluid passes through this valve and returns back to the tractor hydraulic reservoir 51 by hose 102.

[0050] To actuate the upper cylinder 23 the electric thumb switch 20 is activated which opens a port in the electric valve 22 to divert fluid into either, hose 108 or 109 to extend or retract cylinder 23.

[0051] The manual hydraulic valve 42 is used to divert fluid to cylinder 9 by way of hose 130 or 131 to extend or retract this cylinder.

[0052] The manual hydraulic valve 42 is also used to divert fluid to cylinders 3 and 6 (FIG. 1) by hoses 120 or 121 to extend or retract these cylinders as they are actuated to respond simustaineously.

[0053] The electric wiring diagram on FIG. 8 operates as follows: Electric current flows from the tractor coil 45 and fuse 44 through wire 200 to the thumb switch 20 attached to the handle 18 mounted on the hydraulic cylinder 23. When activated, the thumb switch 20 sends an electrical current on wire 201 or 202 to open ports in the electric valve 22 to divert hydraulic fluid through hose 108 or 109 to extend or retract cylinder 23. The electrical circuit is made compete by a ground wire 300 attached to the side of the electric valve 22 which is attached to a jumper wire 301 which completes the circuit for wire 201 or 202 as they are individually energized by the thumb switch 20.

[0054] It is not the intent of the patent applied for to reinvent any of the above patented elements used. Such as the ball-joints, hydraulic cylinders and the electric valve.

[0055] It is the intent however to seek patent for the fixed jaws on the lower arms with the hydraulic locking shafts.

[0056] It is the intent to seek patent for the upper arm fixed and moveable jaw design and application.

[0057] It is also the intent to seek patent for all the above mentioned as they are combined in use to create a new and better designed three-point tractor hitching system.

[0058] It is hoped this invention will not be seen as an obvious conclusion by those skilled in the art to which it pertains because it does not depend on an intermediate hitching device.

[0059] All prior art cited that qualified as a solution to the problems of the three-point hitch, all depend on a separate intermediate device as a hitching agent between the source of power and the implement used. Rather it is the intent to eliminate the need for such device and to redefine the present system.

[0060] While specfic embodiments of the invention have been shown and described, it will be understood, of course, that the invention is not limited thereto since modifications may be made and other embodiments of the principles of this invention will occur to those skilled in the art to which this invention pertains. Therefore, it is contemplated by the appended claims to cover any such modifications and other embodiments as incorporate, the features of this invention within the true spirit and scope of the following claims. 

What is claimed is:
 1. A hitch for securing to an implement for transport by a power source comprising.
 2. A fixed open jaw attached as part to become the trailing ends of the two lower attaching arms that make up the two lower points of the three point tractor hitch system.
 3. A fixed open jaw attached as part to become the trailing ends of the two lower arms that make up the two lower attaching points of the three-point tractor hitch that encompasses the studs of an implement on the bottom, forward and rearward sides.
 4. A hydraulic cylinder mounted adjacent the forward end of the fixed open jaw with a thrusting shaft sufficient in length to close above and over the implement stud to fully encompass the stud and lock by entering the opposing side of the open jaw through an opening made for this purpose.
 5. A pivotally attached hydraulic cylinder to replace and become the upper arm of the three-point tractor hitch system.
 6. A fixed and moveable jaw attached as part to become the trailing end of the hydraulic cylinder that becomes the upper arm of the three-point tractor hitch system.
 7. The fixed portion of the jaw as set forth in claim 6 encompasses the pin carried by the upper center mask of an implement on the top, forward and rearward sides of the pin.
 8. The moveable portion of the jaw as set forth in claim 6 closes around the implement pin from the bottom and locks closed be engaging a latching block attached at the top of the fixed jaw.
 9. The fixed and moveable jaw as set forth in claims 6, 7 and 8, when fully engaged, fully encompasses the implement pin.
 10. The invention as set forth in claim 5 wherein said hydraulic cylinder is an electric valve actuated hydraulic cylinder.
 11. The invention as set forth in claim 10 wherein said electric valve actuated hydraulic cylinder with electric actuated valves to control the flow of hydraulic fluid to the hydraulic cylinder pivotally mounted to become the upper arm of the three-point hitch system.
 12. The invention as set forth in claim 11 said electric valve is activated by a remote attached thumb switch mounted on the handle of the hydraulic cylinder that becomes the upper arm.
 13. The invention as set forth in claims 10, 11, and 12 wherein said electric valve actuated hydraulic cylinder whereas fluid must first enter through the electric valve before entering the hydraulic cylinder whereas the thrust and retract action of the hydraulic cylinder is controlled by the electric valve.
 14. The invention as set forth by the preceding claims whereby said hitch may be easily and quickly secured to an implement by an operator while seated upon the tractor seat and without having to dismount the tractor. 